35 Pa. Stat. § 691.209
On the expiration of the period of time prescribed, after the service of a notice of revocation, modification or change of any such permit from the department, the discharge of sewage into any waters of the Commonwealth or treated sewage from treatment works shall cease and terminate, and the prohibition of this act against such discharge or treatment shall be in full force as though no permit had been granted, but a new permit may thereafter again be granted, as hereinbefore provided. A continuation of the discharge of sewage or the treatment of sewage after revocation, or in violation of any modification and change of any such permit, is hereby also declared to be a nuisance, and shall be punishable and abatable as herein provided.
35 P.S. § 691.209